Sculpting sound and water is an elusive art. For starters, you’re working with an invisible material. Plus, you won’t hear the end product until the plumbing is hooked up and running. “It’s even more difficult to quantify than splash,” says Tom Mallonee, president of CMS Collaborative, based in Santa Cruz, Calif.
What to do?
“Every situation is going to be different, especially in an exterior space,” Mallonee says. “There are no spreadsheets.”
It takes designers years to accumulate the knowledge to fine-tune the auditory aspects of their art. But they started with a few simple rules about the nature of sound and how it responds to its environment.
Following are some guidelines, along with advice on how to make your waterfeatures sing.
Imagine a wheelchair-bound, terminally ill woman who wants to enjoy the sight and melody of water. It’s difficult for her to get around, but what if she could sit on the patio, see the water and hear it gush from hundreds of feet away?
Or consider a client’s joy when he walks down a long series of rills. Each waterfall is a new experience. And every time he steps down, so does the pitch of the next fluid masterpiece.
When you assess the site and design of your waterscape, remember the following four basic rules about sound.
1 Higher tones are directional and can become annoying.
Higher-pitched tones travel on a narrower path, so treble can be easier to control due to its concentration. Point it in the right direction and you’re good to go. But steer it wrong and it can seem relentless. Hard surfaces tend to reflect high notes more than low, so they can potentially send concentrated tone in the wrong place.
This can be especially problematic in indoor spaces or tight, enclosed courtyards where it’s nearly impossible to predict how sound will bounce off the walls. Humans have less tolerance for higher frequencies, according to Mallonee. “Over a certain volume, it’s going to bother people,” he says. “It’s been proven that excessive sound levels at certain frequencies can cause fatigue.”
In his early days, Mallonee designed an indoor fountain in a bank building. The space was covered in hard stone surfaces from floor to ceiling. The sound from the 30-foot-tall, textured granite water wall ricocheted around the room, landing directly in front of the host’s desk at a restaurant. Besides being too loud, the waterfeature emitted a tone that was tough on the eatery’s staff. “It had a lot of hissing, high-frequency sound to it,” Mallonee explains. He adds that if he had the project again today, he would use a smoother wall.
This rule is especially important for indoor installations. “I would stay away from the hissier things and err on the side of a quieter, more low-key effect,” he says. “Where you see lots of foam, you’re going to have high frequencies.” Mallonee also avoids spilling water directly onto stone or other hard surfaces.
If the water breaks up before it hits the final basin, it will emit higher notes. “Those teeny impact points will make a louder, more high-frequency sound,” Mallonee says.
2 Bass travels far and wide.
The rumble of bass will permeate an entire area. It’s loud, but not as concentrated as treble. “You can put bass almost anywhere in the room and not really tell where it’s coming from,” Mallonee says. Bass tones will also travel farther than higher sounds.
Generally, the deeper the basin, the lower the tone, Mallonee says. The purest bass is created by a chute of water free-falling into a deeper basin.
“It’s not being broken up at all, and there’s a lot of force impacting a deeper pool,” explains David Duensing, president of David B. Duensing & Associates Inc. in Ponte Vedra Beach, Fla. The thicker the sheet of water, the deeper the sound. But you don’t want to push hundreds of gallons over a weir, he says. Instead, consider using round boulders to squeeze the water into a narrower channel before it flows into the next pond.
3 Lower tones mute the human voice.
There’s a limit to how deep sound should go because certain ranges make it hard to hear conversation. Duensing has been called in numerous times as a consultant to fix installations that diminished communication.
On one job, he was asked to alter a noisy courtyard waterfeature. The installation was only about a foot tall, with 20 gallons per minute falling into a catch basin. But it directly faced the corner of a courtyard created by an L-shaped house. “When I walked up to the front door, which was part of this L-shaped wall, it was like somebody put earplugs in my ears,” Duensing says. “I couldn’t hear any of the birds, and when the client answered the door, I caught myself leaning in to hear what he was saying.”
Duensing walked to the waterfeature and put his hand inside the 2-foot-deep catch pond, making it shallower. “Suddenly, I could hear the client again and there were birds,” he says. He fixed the problem simply by changing the depth of the basin to 2 inches.
4 Tones disperse off convex surfaces and amplify from concave ones.
When sound hits a convex surface — one that’s curved outward like the side of a ball — the waves will bounce in all directions and distribute evenly throughout the area. “So you’re never standing in a spot where all the sound converges,” Mallonee says. “You’re only hearing sound from one-fifth of the whole wavelength at most.”
Conversely, if a wall curves inward, the reverberations will collect and become magnified. Keep in mind, you can amplify the notes in an area by curving a wall inward, or disperse it by bending a waterfeature wall outward.
Follow the tips below to sculpt your watery orchestra. The results should be music to your clients’ ears.
• Combine sounds.
Don’t rely on a solitary, laminar-type sheet fall, Duensing says. With little to no turbulence, it will create a constant hum that will eventually blend into the background.
Instead, layer the sounds. With rock waterscapes, flow them over a flat piece of stone that will generate a voluminous sheet. Accompany them with rounder rocks, over which the water will cling to emit a babbling effect.
“It’s like a backup band,” says Tim Gillett, owner of Pond Magic Watergardens in Santa Cruz, Calif. “You always have a lead and rhythm guitar, bass at the back and drums. If you don’t have bass, the sound can be shallow.”
Duensing likes to avoid flat stones, instead using textured, round ones for streams and rock waterfalls. With the irregular points of impact and the ability to create channels, the waterfeature will inherently emit many different tones on the scale. “The low, medium and high-pitched sounds are always changing,” he says.
Try using variety when crafting streams. Gillett changes the width throughout. Water drifts gently through expansive areas where people want to read and reflect. The same volume pushing through a narrower channel becomes invigorating. For instance, 4,500 gallons per hour will allow your stream to vary from 1 to 5 feet wide. Going 3 to 5 feet will make the stream more calm and relaxing, whereas 2 feet or less of width will create added energy, he says.
• Actively direct sound.
Chris Kane, co-owner of Kane Brothers Water Features in Burr Ridge, Ill., likes to aim the audio for his waterfeature toward the house. He believes this is where it will be enjoyed the most. If he wants a rambling stream to travel away for some reason, he’ll design it to double back.
You can take more proactive measures, too. Echo chambers send louder, more far-reaching tones in the direction you want. Placed behind the falling water, this cavity acts like a speaker or tiny amphitheater. Sound bounces off the back and travels out in a fan.
Randy Tumber, president of Tumber and Associates in Orangeville, Ontario, Canada, shapes his like a modified V, with the opening wider than the back. Echo chambers that are deeper from front to back will send the wavelengths out farther.
The harder and smoother the interior surface, the purer the sound. Rougher textures may distort the sound. This adds a new tone, as if you were hearing two waterfalls, Duensing says.
On the project for the wheelchair-bound client described earlier, the waterfall sent sound almost 1/4-mile to the back porch. It was 6 feet tall and generated 200 gallons per minute, but Tumber credits the echo chamber for its success. “If I had turned the echo chamber toward the fire pit terrace, it would have ruined the whole concept,” he says.
When building a stream or pond with several waterfeatures, point each one to a separate destination spot. For instance, do you need sound to travel farther toward the master bedroom? Point a larger, deeper fall in that direction and use an echo chamber to propel the sound. A more soothing waterfeature can trickle near a conversation pit.
• Try creative ways to add or subtract sound.
Anthony Archer-Wills, a renowned water-garden designer based in Copake Falls, N.Y., minimizes sound in a unique way. On one installation, for example, he set up a round millstone, where water welled up through a hole in the center, ran across the surface and then dropped off.
He didn’t want water to fall the entire 18 inches to the pool, so he draped aquatic moss off the edges. Water wicked down the moss until it hung a few inches above the pool and then trickled down. It still had a dramatic look, but emitted a more subtle timbre.
• Overbuild now, so you can do the fine-tuning later.
Fine-tuning takes place once the aquascape is running and you can hear how it sounds.
With rock waterfeatures, you can reduce a rumble, but you can’t build up from a purr. Therefore, oversize each fall and catch basin, and valve the plumbing for future flow adjustments. If a fall is too loud, add rocks to the echo chamber or ratchet down the flow. If the pitch is too low, add material to make the catch basin more shallow.
For the low-key water gardens Duensing builds, he likes to construct each basin about a foot below the expected water level. Then he’ll add rocks until he reaches a depth that creates the sound he wants. In addition, Duensing might choose to leave some joints between the rocks unsealed. That way, water disperses through those cracks rather than making more impact in the pond.
For his streams, Gillett typically adds a foot to the expected depth so he has plenty of wiggle room.
One noteworthy exception to this rule: If you’re designing a waterfeature that can’t be adjusted after construction, always underbuild, Mallonee says. Overly boisterous water is more offensive than a sound that’s too soft.
• Replicate the noise you want to mask.
You probably can’t drown out road noise, airplanes or other strong intrusions, so don’t try to obliterate them with volume. Instead, replicate the nuisance’s tone as closely as possible.
“If it’s a light sound, you might try a fountain, or gentle splashing over tiles or fine rocks,” Archer-Wills says. “If it’s a deep sound you’re trying to deal with such as trucks, you might prefer a waterfall with a deep undercut to get a dull, booming effect.”
To truly distract from road noise, a layering of sounds works best. “Once you start to mix in other sounds, you begin to pay less attention to the traffic noise,” Kane says.